In chemical vapor deposition, after canister changes and process runs, the residual chemicals remaining in the metal delivery lines and containers must be thoroughly cleaned Organometallic precursors and inorganic chemicals are used in the deposition of thin films using chemical vapor deposition (CVD) or atomic layer deposition (ALD) techniques. Many of these precursors are extremely sensitive to air and decompose rapidly in the presence of oxygen, water, or high temperature. The decomposition products contaminate the deposition chambers and delivery lines.
A common method employed to prevent contamination is to flush the delivery lines with a solvent. Presently, hydrocarbon solvents are the most commonly used solvents. Examples include pentane, hexane, and octane. However, the chemical precursors used in chemical vapor deposition have limited solubility in such solvents. Thus, high volumes of these solvents are required in order to effectively remove the residual precursors. Furthermore, some of these solvents have relatively low vapor pressures, making them difficult to dry. In some cases, existing solvents may contain unacceptable levels of moisture, which may contaminate and corrode the deposition chambers and delivery lines.
Consequently, there is a need for a universal, stable solvent that is capable of dissolving CVD precursors and has a high enough vapor pressure to achieve a desired rate of drying.